<ul>
    <li><?php echo anchor('index.php/main/create', 'Create')?></li>
    <li><?php echo anchor('index.php/main/retrieve', 'Retrieve')?></li>
    <li><?php echo anchor('index.php/main/update', 'Update')?></li>
    <li><?php echo anchor('index.php/main/delete', 'Delete')?></li>
</ul>